Numbers whose binary expansion does not begin 100.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =5a(5) =6a(6) =7a(7) =10a(8) =11a(9) =12a(10) =13a(11) =14a(12) =15a(13) =20a(14) =21a(15) =22a(16) =23a(17) =24a(18) =25a(19) =26a(20) =27a(21) =28a(22) =29a(23) =30a(24) =31a(25) =40a(26) =41a(27) =42a(28) =43a(29) =44